Check and clear date cache in DateCurrentTime, DateLocalTimezone and getTimezoneOffset.

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 9597 matching lines @@
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DateCurrentTime) {
   SealHandleScope shs(isolate);
   ASSERT(args.length() == 0);
 
   // According to ECMA-262, section 15.9.1, page 117, the precision of
   // the number in a Date object representing a particular instant in
   // time is milliseconds. Therefore, we floor the result of getting
   // the OS time.
   double millis = std::floor(OS::TimeCurrentMillis());
+  isolate->date_cache()->CheckTimezone();
   return isolate->heap()->NumberFromDouble(millis);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DateParseString) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 2);
 
   CONVERT_ARG_HANDLE_CHECKED(String, str, 0);
   FlattenString(str);
@@ skipping 26 matching lines @@
     return isolate->heap()->null_value();
   }
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DateLocalTimezone) {
   SealHandleScope shs(isolate);
   ASSERT(args.length() == 1);
 
   CONVERT_DOUBLE_ARG_CHECKED(x, 0);
+  isolate->date_cache()->CheckTimezone();
   int64_t time = isolate->date_cache()->EquivalentTime(static_cast<int64_t>(x));
   const char* zone = OS::LocalTimezone(static_cast<double>(time));
   return isolate->heap()->AllocateStringFromUtf8(CStrVector(zone));
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DateToUTC) {
   SealHandleScope shs(isolate);
   ASSERT(args.length() == 1);
 
@@ skipping 5291 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal